diff --git a/src/credits/credits.ts b/src/credits/credits.ts
index c82ce45..d78b03f 100644
--- a/src/credits/credits.ts
+++ b/src/credits/credits.ts
@@ -147,7 +147,6 @@ export async function addCredits({
       .update(userCredit)
       .set({
         currentCredits: newBalance,
-        // lastRefreshAt: new Date(), // NOTE: we can not update this field here
         updatedAt: new Date(),
       })
       .where(eq(userCredit.userId, userId));
@@ -158,7 +157,6 @@ export async function addCredits({
       id: randomUUID(),
       userId,
       currentCredits: newBalance,
-      // lastRefreshAt: new Date(), // NOTE: we can not update this field here
       createdAt: new Date(),
       updatedAt: new Date(),
     });
diff --git a/src/db/schema.ts b/src/db/schema.ts
index 81e0df1..ad8c17e 100644
--- a/src/db/schema.ts
+++ b/src/db/schema.ts
@@ -94,7 +94,7 @@ export const userCredit = pgTable("user_credit", {
 	id: text("id").primaryKey(),
 	userId: text("user_id").notNull().references(() => user.id, { onDelete: 'cascade' }),
 	currentCredits: integer("current_credits").notNull().default(0),
-	lastRefreshAt: timestamp("last_refresh_at"),
+	lastRefreshAt: timestamp("last_refresh_at"), // deprecated
 	createdAt: timestamp("created_at").notNull().defaultNow(),
 	updatedAt: timestamp("updated_at").notNull().defaultNow(),
 }, (table) => ({